Microstructural Characterization of Thermal Barrier Coatings Deposited by APS and LPPS Thin Film Methods

Abstract

In the paper first results of TBCs deposition by LPPS-Thin Film method were presented. The LPPS-Thin Film is a new type of processes for deposition of thermal barrier coatings. In this method deposition of thin ceramic layer in very low pressure is possible as well as coatings with columnar structure (in plasma spraying-physical vapour deposition process). The MeCrAlY bond coats were deposited by APS method. The overaluminising by CVD method of conventional MeCrAlY was also conducted. The analysis of microstructure of both type bond coats as well as outer ceramic layer were presented using light and scanning electron microscopy methods. Results of EDS microanalysis showed the increasing of aluminum content in outer zone of overaluminized MeCrAlY coating. In ceramic layer the columnar structure were observed which was connected with powder evaporation during plasma spraying. The new type of MeCrAlY-NiAl bondcoat could increase the oxidation of TBCs deposited by LPPS Thin Film method.